diff --git a/mlir/include/mlir/IR/OpImplementation.h b/mlir/include/mlir/IR/OpImplementation.h
--- a/mlir/include/mlir/IR/OpImplementation.h
+++ b/mlir/include/mlir/IR/OpImplementation.h
@@ -572,12 +572,10 @@
   virtual ParseResult parseOptionalString(std::string *string) = 0;
 
   /// Parse a given keyword.
-  ParseResult parseKeyword(StringRef keyword, const Twine &msg = "") {
-    auto loc = getCurrentLocation();
-    if (parseOptionalKeyword(keyword))
-      return emitError(loc, "expected '") << keyword << "'" << msg;
-    return success();
+  ParseResult parseKeyword(StringRef keyword) {
+    return parseKeyword(keyword, "");
   }
+  virtual ParseResult parseKeyword(StringRef keyword, const Twine &msg) = 0;
 
   /// Parse a keyword into 'keyword'.
   ParseResult parseKeyword(StringRef *keyword) {
diff --git a/mlir/include/mlir/Parser/CodeComplete.h b/mlir/include/mlir/Parser/CodeComplete.h
--- a/mlir/include/mlir/Parser/CodeComplete.h
+++ b/mlir/include/mlir/Parser/CodeComplete.h
@@ -43,6 +43,11 @@
   /// completions.
   virtual void appendBlockCompletion(StringRef name) = 0;
 
+  /// Signal a completion for the given expected tokens, which are optional if
+  /// `optional` is set.
+  virtual void completeExpectedTokens(ArrayRef<StringRef> tokens,
+                                      bool optional) = 0;
+
 protected:
   /// Create a new code completion context with the given code complete
   /// location.
diff --git a/mlir/lib/Parser/AsmParserImpl.h b/mlir/lib/Parser/AsmParserImpl.h
--- a/mlir/lib/Parser/AsmParserImpl.h
+++ b/mlir/lib/Parser/AsmParserImpl.h
@@ -242,8 +242,21 @@
     return success();
   }
 
+  ParseResult parseKeyword(StringRef keyword, const Twine &msg) override {
+    if (parser.getToken().isCodeCompletion())
+      return parser.codeCompleteExpectedTokens(keyword);
+
+    auto loc = getCurrentLocation();
+    if (parseOptionalKeyword(keyword))
+      return emitError(loc, "expected '") << keyword << "'" << msg;
+    return success();
+  }
+
   /// Parse the given keyword if present.
   ParseResult parseOptionalKeyword(StringRef keyword) override {
+    if (parser.getToken().isCodeCompletion())
+      return parser.codeCompleteOptionalTokens(keyword);
+
     // Check that the current token has the same spelling.
     if (!parser.isCurrentTokenAKeyword() ||
         parser.getTokenSpelling() != keyword)
@@ -267,6 +280,9 @@
   ParseResult
   parseOptionalKeyword(StringRef *keyword,
                        ArrayRef<StringRef> allowedKeywords) override {
+    if (parser.getToken().isCodeCompletion())
+      return parser.codeCompleteOptionalTokens(allowedKeywords);
+
     // Check that the current token is a keyword.
     if (!parser.isCurrentTokenAKeyword())
       return failure();
diff --git a/mlir/lib/Parser/Parser.h b/mlir/lib/Parser/Parser.h
--- a/mlir/lib/Parser/Parser.h
+++ b/mlir/lib/Parser/Parser.h
@@ -319,6 +319,8 @@
   ParseResult codeCompleteOperationName(StringRef dialectName);
   ParseResult codeCompleteDialectOrElidedOpName(SMLoc loc);
   ParseResult codeCompleteStringDialectOrOperationName(StringRef name);
+  ParseResult codeCompleteExpectedTokens(ArrayRef<StringRef> tokens);
+  ParseResult codeCompleteOptionalTokens(ArrayRef<StringRef> tokens);
 
 protected:
   /// The Parser is subclassed and reinstantiated.  Do not add additional
diff --git a/mlir/lib/Parser/Parser.cpp b/mlir/lib/Parser/Parser.cpp
--- a/mlir/lib/Parser/Parser.cpp
+++ b/mlir/lib/Parser/Parser.cpp
@@ -395,6 +395,15 @@
   return failure();
 }
 
+ParseResult Parser::codeCompleteExpectedTokens(ArrayRef<StringRef> tokens) {
+  state.codeCompleteContext->completeExpectedTokens(tokens, /*optional=*/false);
+  return failure();
+}
+ParseResult Parser::codeCompleteOptionalTokens(ArrayRef<StringRef> tokens) {
+  state.codeCompleteContext->completeExpectedTokens(tokens, /*optional=*/true);
+  return failure();
+}
+
 //===----------------------------------------------------------------------===//
 // OperationParser
 //===----------------------------------------------------------------------===//
diff --git a/mlir/lib/Tools/mlir-lsp-server/MLIRServer.cpp b/mlir/lib/Tools/mlir-lsp-server/MLIRServer.cpp
--- a/mlir/lib/Tools/mlir-lsp-server/MLIRServer.cpp
+++ b/mlir/lib/Tools/mlir-lsp-server/MLIRServer.cpp
@@ -690,6 +690,16 @@
     completionList.items.emplace_back(item);
   }
 
+  /// Signal a completion for the given expected token.
+  void completeExpectedTokens(ArrayRef<StringRef> tokens, bool optional) final {
+    for (StringRef token : tokens) {
+      lsp::CompletionItem item(token, lsp::CompletionItemKind::Keyword);
+      item.sortText = "0";
+      item.detail = optional ? "optional" : "";
+      completionList.items.emplace_back(item);
+    }
+  }
+
 private:
   lsp::CompletionList &completionList;
   MLIRContext *ctx;
diff --git a/mlir/test/mlir-lsp-server/completion.test b/mlir/test/mlir-lsp-server/completion.test
--- a/mlir/test/mlir-lsp-server/completion.test
+++ b/mlir/test/mlir-lsp-server/completion.test
@@ -100,6 +100,39 @@
 // CHECK:         ]
 // CHECK-NEXT:  }
 // -----
+{"jsonrpc":"2.0","id":1,"method":"textDocument/completion","params":{
+  "textDocument":{"uri":"test:///foo.mlir"},
+  "position":{"line":0,"character":10}
+}}
+//      CHECK:  "id": 1
+// CHECK-NEXT:  "jsonrpc": "2.0",
+// CHECK-NEXT:  "result": {
+// CHECK-NEXT:    "isIncomplete": false,
+// CHECK-NEXT:    "items": [
+// CHECK-NEXT:      {
+// CHECK-NEXT:        "detail": "optional",
+// CHECK-NEXT:        "insertTextFormat": 1,
+// CHECK-NEXT:        "kind": 14,
+// CHECK-NEXT:        "label": "public",
+// CHECK-NEXT:        "sortText": "0"
+// CHECK-NEXT:      },
+// CHECK-NEXT:      {
+// CHECK-NEXT:        "detail": "optional",
+// CHECK-NEXT:        "insertTextFormat": 1,
+// CHECK-NEXT:        "kind": 14,
+// CHECK-NEXT:        "label": "private",
+// CHECK-NEXT:        "sortText": "0"
+// CHECK-NEXT:      },
+// CHECK-NEXT:      {
+// CHECK-NEXT:        "detail": "optional",
+// CHECK-NEXT:        "insertTextFormat": 1,
+// CHECK-NEXT:        "kind": 14,
+// CHECK-NEXT:        "label": "nested",
+// CHECK-NEXT:        "sortText": "0"
+// CHECK-NEXT:      }
+// CHECK-NEXT:    ]
+// CHECK-NEXT:  }
+// -----
 {"jsonrpc":"2.0","id":3,"method":"shutdown"}
 // -----
 {"jsonrpc":"2.0","method":"exit"}